Composition

ABSTRACT

The present invention relates to a composition comprising a photo-bleaching component and a fluorescent whitening component having good compatibility. In particular, the present invention relates to a composition suitable for the treatment of textiles, comprising a photo-bleaching component and a fluorescent whitening component, wherein the photo-bleaching component is capable of absorbing light to form an intermediate energetically excited photo-bleaching component, the intermediate energetically excited photo-bleaching component is capable of activating molecular oxygen from its triplet oxygen electronic energy state to its singlet oxygen electronic energy state, characterised in that the intermediate energetically excited photo-bleaching component has a lifetime of greater than 50 microseconds, preferably greater than 100 microseconds, more preferably greater than 200 microseconds, and most preferably greater than 300 microseconds.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 60/492888 filed Aug. 6, 2003.

TECHNICAL FIELD

The present invention relates to a composition suitable for the treatment of textiles, especially a laundry detergent composition, comprising a compatible photo-bleaching component and a fluorescent whitening component.

BACKGROUND TO THE INVENTION

Consumers, especially those living in countries having an ample supply of sunshine, and also those consumers living in the UK, typically dry their recently laundered garments outside in the sunlight. Detergent manufactures make use of this consumer habit to give benefits to recently laundered garments by incorporating technologies, such as photo-bleach and fluorescent whitening agents into their laundry detergent products; for example, to provide post-wash bleaching benefits and fabric whitening benefits. Detergent manufactures have formulated laundry detergents comprising both photo-bleach and fluorescent whitening agents; for example, U.S. Pat. No. 4,311,605 relates to compositions comprising photo-bleach and fluorescent whitening agents, which allegedly results in a synergistic bleaching and whitening effect.

Photo-bleach is capable of absorbing light in the visible wavelength band to form an intermediate energetically excited photo-bleach, which is capable of activating molecular oxygen from its triplet oxygen electronic energy state to its singlet oxygen electronic energy state. Singlet oxygen is a potent bleach that is capable of oxidising a vast array of substrates, including many soils typically encountered and cleaned in laundering processes.

Fluorescent whitening agents are capable of absorbing light in the ultraviolet wavelength band and re-emitting light in the visible wavelength band. Typically, light in the blue region of the visible wavelength band is re-emitted, giving the recently laundered garments a consumer preferred bluish hue. This bluish hue is especially preferred when the laundered garments are white in colour and comprise natural cotton as the bluish hue masks the yellowness of the natural cotton fibres.

The Inventors have surprisingly identified that there is a compatibility issue with photo-bleach and fluorescent whitening agents when present in the same detergent formulation, and that the combination of these two components in the laundry detergent composition does not always give both an effective photo-bleaching benefit and an effective whitening benefit. Indeed the Inventors have surprisingly found that there is a tendency of the fluorescent whitening agent to diminute the performance of the photo-bleach. Without wishing to be bound by theory, the Inventors believe that the fluorescent whitening agent competes with molecular oxygen for the energy released by the excited triplet state of the photo-bleach (which is the intermediate energetically excited photo-bleaching component), thus diminishing formation of singlet oxygen and its subsequent bleaching effect.

This problem of incompatibility of photo-bleach and fluorescent whitening agents has not been identified in the prior art. There was no reason whatsoever to suspect an incompatibility problem between photo-bleach and fluorescent whitening agents as it was believed that the photo-bleaching mechanism and the fluorescent whitening mechanism were completely independent mechanisms, absorbing light from different wavelength bands, and the wavelength of the light re-emitted by the fluorescent whitening agent is substantially different from the wavelength of light absorbed by the photo-bleach.

The Inventors have surprisingly overcome this incompatibility problem by ensuring that, when the photo-bleach is formulated with a fluorescent whitening agent, the intermediate energetically excited photo-bleaching component has a prolonged lifetime. This is achieved by careful selection of the photo-bleach and fluorescent whitening agent to be formulated together in the same laundry detergent composition.

SUMMARY OF THE INVENTION

The present invention provides a composition suitable for the treatment of textiles, comprising a photo-bleaching component and a fluorescent whitening component, wherein the photo-bleaching component is capable of absorbing light to form an intermediate energetically excited photo-bleaching component, the intermediate energetically excited photo-bleaching component is capable of activating molecular oxygen from its triplet oxygen electronic energy state to its singlet oxygen electronic energy state, characterised in that the intermediate energetically excited photo-bleaching component has a lifetime of greater than 50 microseconds.

DETAILED DESCRIPTION OF THE INVENTION

Composition

The composition is suitable for the treatment of textiles. In particular, the composition is a laundry detergent composition. The composition can be in particulate form or in liquid form. Typically, the composition is in particulate form, for example in the form of an agglomerate, a spray-dried powder, an extrudate, a flake, or any combination thereof. The composition may also be in tablet form or other unit dose form such as a pouch. The composition may be at least partially enclosed, or preferably completely enclosed, by a water-soluble film such as film comprising polyvinyl alcohol. However, typically, the composition is a granular laundry detergent composition.

The composition comprises a photo-bleaching component, which is described in more detail below. The composition also comprises a fluorescent whitening component, which is described in more detail below. The composition may also comprise additional adjunct components, which are described in more detail below. Preferably, the composition is a laundry detergent composition comprising a photo-bleaching component, a fluorescent whitening component, a detersive surfactant, a builder, optionally bleach and optionally other adjunct detergent components.

Photo-Bleaching Component

The photo-bleaching component is capable of absorbing light to form an intermediate energetically excited photo-bleaching component. The intermediate energetically excited photo-bleaching component is capable of activating molecular oxygen from its triplet oxygen electronic state to its singlet oxygen electronic energy state. The molecular oxygen in its singlet oxygen electronic energy state is capable of oxidising a vast array of substrates by a variety of mechanisms including ene reactions and cyclo-addition reactions. An example of an ene reaction is given below:

An example of a cyclo-addition reaction is given below:

The process for the generation of molecular oxygen in its singlet oxygen electronic energy state is given in more detail below:

Light absorption by the photo-bleaching component P leads to the formation of an intermediate photo-bleaching component P (S), typically in its singlet excited state. As oxygen has a triplet ground state, the intermediate photo-bleaching component P (S) must undergo intersystem crossing (ISC) to form an intermediate energetically excited photo-bleaching component P (T), typically in its triplet excited state, in order to interact with ground state oxygen. Intersystem crossing generally proceeds with good efficiency. Once the intermediate energetically excited photo-bleaching component P (T) is formed, collision with molecular oxygen (in its triplet oxygen electronic energy state) can lead to energy transfer to the molecular oxygen and the formation of molecular oxygen in its singlet oxygen electronic energy state. Once formed, the molecular oxygen in its singlet oxygen electronic state is reactive with a range of substrates, as described above in more detail.

The intermediate energetically excited photo-bleaching component has a lifetime of greater than 50 microseconds, preferably greater than 100 microseconds, more preferably greater than 200 microseconds, and most preferably greater than 300 microseconds. The lifetime of the intermediate energetically excited photo-bleaching component is described in more detail below. The lifetime of the intermediate energetically excited photo-bleaching component is the lifetime of the above component when in the presence of the fluorescent whitening component.

Preferably the photo-bleaching component is a sulphonated phthalocyanine having an average degree of sulphonation of from greater than 3.0 to less than 4.0, preferably from 3.8 to less than 4.0, the sulphonated phthalocyanine being complexed with a metal cation. Typically, the sulphonated phthalocyanine is not substituted with a halide group. Preferably, the photo-bleaching agent is a sulphonated zinc phthalocyanine having an average degree of sulphonation of from greater than 3.0 to less than 4.0, preferably 3.8 to less than 4.0. The photo-bleaching component may be a sulphonated tin phthalocyanine, a sulphonated tin naphthalocyanine or a mixture thereof. The photo-bleaching component may be a sulphonated zinc naphthalocyanine, a sulphonated aluminium naphthalocyanine, a sulphonated tin naphthalocyanine or any mixture thereof. The photo-bleaching component may preferably be a mixture of a sulphonated zinc phthalocyanine and a sulphonated aluminium phthalocyanine, wherein the molar ratio of the sulphonated zinc phthalocyanine to sulphonated aluminum phthalocyanine is less than 3:1, preferably less than 2:1.

Other photo-bleaching components that may be suitable for use in the present invention are those described in more detail by A. D. Willey in Powdered Detergents, ed. M. Showell, Surfactant Series Vol 71, Marcel Dekker, New York, 1998, p185-203.

Optionally, the photo-bleaching component may be encapsulated. Suitable encapsulating materials are described in more detail in WO03/018738 and WO03/18740. A preferred encapsulating material is starch.

Fluorescent Whitening Component

Fluorescent whitening components are typically capable of absorbing light in the ultraviolet wavelength band and re-emitting light in the visible band. Typically light in the blue region of the visible wavelength band is re-emitted, giving recently treated fabris a consumer preferred bluish hue. Preferably, the fluorescent whitening component is a substituted stilbenesulphonic acid or a salt thereof that is substituted by at least one triazol-2-yl moiety. Preferably, the fluorescent whitening component is a molecule having the general formula:

Preferably, the fluorescent whitening component is a molecule having the general formula:

Another brightener than may be suitable for use in the present invention is Sodium dibenzobiphenyldisulfonate.

Other preferred fluorescent whitening components that may be suitable for use in the present invention are described in more detail by L. Ho Tan Tai, in Formulating Detergents and Personal Care Products: A complete guide to Product Development, AOCS Press, Champaign, 2000, p122-137.

Prolonged Lifetime of the Intermediate Energetically Excited Photo-Bleaching Component

The Inventors have surprisingly found that good compatibility between the photo-bleaching component and the fluorescent whitening component is achievable by ensuring that the lifetime of the intermediate energetically excited photo-bleaching component (when in the presence of the fluorescent whitening component) is at least 50 microseconds, preferably at least 100 microseconds, more preferably at least 200 microseconds and most preferably at least 300 microseconds. This can be achieved, for example, by careful selection of fluorescent whitening components and photo-bleaching components to be used in combination with each other.

Typically, the lifetime of the intermediate energetically excited photo-bleaching component (when in the presence of the fluorescent whitening component) is very short. For example, the lifetime of the intermediate energetically excited photo-bleaching component of a sulphonated zinc phthalocyanine photo-bleaching component when used in combination with a disodium 4,4′-bis-(2-sulphostyryl)biphenyl fluorescent whitening component, is 3 microseconds. The lifetime of the intermediate energetically excited photo-bleaching component of a sulphonated zinc phthalocyanine photo-bleaching component when used in combination with a disodium-4,4′-bis[(4-anilino-6-morpholino-s-triazin-2-yl)-amino]-2,2′-stilbenedisulfonate, is 4 microseconds. The lifetime of the intermediate energetically excited photo-bleaching component of a sulphonated zinc phthalocyanine photo-bleaching component when used in combination with a disodium-4,4′-bis[(4,6-dianilino-s-triazin-2-yl)-amino]-2,2′-stilbenedisulfonate, is 4 microseconds. All of these combinations give very poor photo-bleaching performance, especially in laundry cleaning applications. These combinations having a low lifetime for the intermediate energetically excited photo-bleaching component, are all outside of the claim-scope and are not in accordance with the present invention.

However, the lifetime of an intermediate energetically excited photo-bleaching component of a sulphonated zinc phthalocyanine having an average degree of sulphonation of from greater than 3.0 to less than 4.0, and especially from 3.8 to less than 4.0, when used in combination with a fluorescent whitening component that is the sodium salt of 4,4′-bis-(4-phenyl-1,2,3-triazol-2-yl)-2,2′-stilbene-disulphonic acid, is 310 microseconds, and good photo-bleaching performance and good whiteness performance is observed. This careful selection of photo-bleaching component and fluorescent whitening component is far greater than lifetime compared to the former above described combinations that have lifetimes of only 3, 4 and 8 microseconds, respectively.

The lifetime of the intermediate energetically excited photo-bleaching component is typically determined using flash photolysis, for example by using a Nd-YAG laser (Lumonics Ltd) as the excitation source, a 250 W xenon arc lamp (Applied Photophysics Ltd) as the analyzing source and a R928 photomultiplier (Hanamatsu Ltd) as the detector. One suitable flash photolysis method that can be used to determine the lifetime of the intermediate energetically excited photo-bleaching component is described in more detail by C. Willsher, Journal of the Society of Dyers and Colourists, 1988, Vol 104, p472-476.

The skilled person, in light of the disclosure of the present invention, can calculate the lifetime of the intermediate energetically excited photo-bleaching component in the presence of a particular fluorescent whitening component with no undue burden, and the skilled person can select combinations of a photo-bleaching component and a fluorescent whitening component, having good photo-bleaching performance and whitening benefits that are in accordance with the present invention.

Adjunct Detergent Components

The composition may optionally comprise one or more adjunct detergent components. These adjunct detergent components are typically selected from the group consisting of detersive surfactants, builders, polymeric co-builders, bleach, chelants, enzymes, anti-redeposition polymers, soil-release polymers, polymeric soil-dispersing and/or soil-suspending agents, dye-transfer inhibitors, fabric-integrity agents, suds suppressors, fabric-softeners, flocculants, perfumes and combinations thereof. Suitable adjunct components are described in more detail in WO97/11151, especially from page 15, line 31 to page 27, line 27, and from page 28, line 5 to page 56, line 24, and from page 48, line 2 to page 50, line 4.

EXAMPLES

The following granular laundry detergent compositions A-F having a bulk density of from 440 g/l to 580 g/l, are in accordance with the present invention. Ingredient A B C D E F Sodium C₁₂-C₁₅ alkyl 0.9 0.6 0.8 0.7 sulfate condensed with an average of 3 moles of ethylene oxide Sodium linear C₁₁-C₁₃ 22 16 17 28 19 17 alkyl benzene sulfonate Cationic surfactant having 0.4 0.7 0.5 0.8 0.6 0.5 the general formula: R₂.N⁺(CH₃)₂(C₂H₄OH), wherein R₂ = C₁₂-C₁₄ Sodium carbonate 14 16 6 15 8 9 Sodium silicate 5 9 17 6 10 8 Sodium sulfate 5 10 21 14 19 25 Sodium tripolyphosphate 32 26 26 30 28 Zeolite A 30 Diethylene triamine 0.3 0.4 0.7 0.6 0.4 0.3 pentaacetic acid Magnesium sulfate 1.1 1.6 Sodium perborate bleach 4 3 of nominal formula: NaBO₃.H₂O (6-nonamidocaproyl) 1.8 oxybenzene sulfonate Nonanoyloxybenzene 1.5 sulfonate Tetra-acetyl-ethylene- 0.55 0.7 diamine Photo-bleaching 0.0018 0.003 0.001 component that is a sulfonated zinc phthalocyanine, with an average degree of sulfonation of 3.95 Photo-bleaching 0.0012 0.002 0.004 0.003 component that is a sulfonated alumino phthalocyanine, with an average degree of sulfonation of 3.95 Fluorescent whitening 0.1 0.05 0.1 0.15 0.05 component that is a disodium 4,4′-bis-(4- phenyl-1,2,3-triazol-2-yl)- 2,2′-stilbene- disulphonate, supplied by Bayer under the tradename Blankophor BHC. Fluorescent whitening 0.05 0.2 0.05 0.05 component that is a sodium 4-[2H- naphtho[1,2-d]triazol-2- yl]stilbene-2-sulfonate, supplied by Ciba under the tradename Tinopal RBS Fluorescent whitening 0.05 0.1 0.12 component that is a sulfonated, methylated dibenzofuran biphenyl (CAS 133-057-91-7), supplied by Ciba-Geigy under the tradename Tinopal PLC Amylase 0.2 0.1 0.3 Cellulase 0.2 0.2 0.1 Protease 0.2 0.2 0.5 0.1 Perfume 0.1 0.4 0.3 0.25 0.3 Moisture and to to to to to to miscellaneous 100% 100% 100% 100% 100% 100%

All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention.

While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. 

1. A composition suitable for the treatment of textiles, comprising a photo-bleaching component and a fluorescent whitening component, wherein the photo-bleaching component is capable of absorbing light to form an intermediate energetically excited photo-bleaching component, the intermediate energetically excited photo-bleaching component is capable of activating molecular oxygen from its triplet oxygen electronic energy state to its singlet oxygen electronic energy state, characterised in that the intermediate energetically excited photo-bleaching component has a lifetime of greater than 50 microseconds.
 2. A composition according to claim 1, wherein the intermediate energetically excited photo-bleaching component has a lifetime of greater than 100 microseconds.
 3. A composition according to claim 1, wherein the intermediate energetically excited photo-bleaching component has a lifetime of greater than 200 microseconds.
 4. A composition according to claim 1, wherein the intermediate energetically excited photo-bleaching component has a lifetime of greater than 300 microseconds.
 5. A composition according to claim 1, wherein the photo-bleaching component is a sulphonated phthalocyanine having an average degree of sulphonation of from greater than 3.0 to less than 4.0 that is complexed with a metal cation, and wherein the sulphonated phthalocyanine is not substituted with a halide group.
 6. A composition according to claim 5, wherein the sulphonated phthalocyanine has an average degree of sulphonation of from 3.8 to less than 4.0.
 7. A composition according to claim 1, wherein the photo-bleaching agent is a sulphonated zinc phthalocyanine having an average degree of sulphonation of from greater than 3.0 to less than 4.0.
 8. A composition according to claim 7, wherein the sulphonated zinc phthalocyanine has an average degree of sulphonation of from 3.8 to less than 4.0.
 9. A composition according to claim 1, wherein the photo-bleaching component is a sulphonated tin phthalocyanine, a sulphonated tin naphthalocyanine or a mixture thereof.
 10. A composition according to claim 1, wherein the photo-bleaching component is a sulphonated zinc naphthalocyanine, a sulphonated aluminium naphthalocyanine, a sulphonated tin naphthalocyanine or any mixture thereof.
 11. A composition according to claim 1, wherein the photo-bleaching component is a mixture of a sulphonated zinc phthalocyanine and a sulphonated aluminium phthalocyanine, wherein the molar ratio of the sulphonated zinc phthalocyanine to sulphonated aluminum phthalocyanine is less than 3:1.
 12. A composition according to claim 11, wherein the molar ratio of the sulphonated zinc phthalocyanine to sulphonated aluminum phthalocyanine is less than 2:1.
 13. A composition according to claim 1, wherein the fluorescent whitening component is a substituted stilbenesulphonic acid or a salt thereof that is substituted by at least one triazol-2-yl moiety.
 14. A composition according to claim 1, wherein the fluorescent whitening component is a molecule having the general formula:


15. A composition according to claim 1, wherein the fluorescent whitening component is a molecule having the general formula:


16. A composition according to claim 1, wherein the composition is a laundry detergent composition and additionally comprises a detersive surfactant, a builder, optionally bleach and optionally other adjunct detergent components.
 17. A method of treating a fabric comprising the step of contacting a composition according to claim 1 with water to form an aqueous wash liquor, and contacting the aqueous wash liquor with a fabric. 